1. Field of the Invention
The apparatus of the present invention relates to indicators with lenses. More particularly, the apparatus of the present invention relates to an indicator having a light emitting diode or bulb for indicating the operative state of the indicator valve through the lens body.
2. General Background
In various aspects of industrial and commercial uses, very often there is utilized a viewing lens to indicate to a viewer, or a person whose duty it is to monitor an indicator valve, the status of a particular system by color changes viewed in the lens. In a common industrial use, indicators have been used in certain types of valves, for example relay valves, wherein the valve is variable between an open and shut position, the open position allowing flow of fluids through the valve to an actuator in order to allow an oil well or the like to continue in production. Should there be a failure in the system, the relay would "shut-in" due to a change in a measured quantity, and the valve would shift from an opened to a closed position. Of course, in order to facilitate an operator knowing when the valve is in the opened or closed position, a type of indicator has been used throughout the years, in order to assist in that determination. What has become standard in the industry, is the use of a color coded indicator, wherein green would signify the valve is in the open position, and red would signify the valve in the closed position, thus indicating a problem in the system.
There is one type of indicator which has been utilized wherein the valve provides an internal stem which moves longitudinally within a bore in the valve so that internal pressure on the end of the stem provided with a piston would move the stem to an "up" position, the loss of pressure on the same end of the stem would move the stem back to the "down" position. In this particular indicator, the head of the stem is provided with green and red bands of color which when shifted from the down to the up position, the red or green band of color respectively will appear through a lens provided at the top of the valve for indicating the position of the valve. In order to give the operator a better view of the red or green color indication, a type of lucite (or plastic) lens has been used which would help to properly reflect the particular color as indicated.
In fact, B.W.B. Controls, Inc, is presently assigned an application for such an improved indicator lens, wherein an angulated indicator lens secured to the top portion of a relay valve would provide maximum refraction and disbursement of the several indicating colors on the valve stem. The lens body would have an interior angulated truncated surface of approximately 45.degree. to the horizontal, with an exterior angulated, truncated upper surface of approximately 54.degree. to the vertical. In the preferred embodiment, the transparent lens body would receive ambient red light from the stem providing the maximum refraction of light onto the first interior angulated surface and directing the color to be indicated through the lens medium and onto the second exterior angulated, truncated surface for maximum indicating area.
In describing the apparatus of the present invention, applicant shall make reference to this particular type of new lens, in order to more properly describe the optimum operation of the apparatus. However, it should be kept in mind that this particular apparatus, i.e., the light-emitting indicator, can be used with several of the type of lens presently on the market, and is not restricted to this particular type of indicator lens as will be described more fully in the specification and used in conjunction with the apparatus.